Cyprian Ogombe Odoli
Cyprian Ogombe Odoli (PhD) works at Kenya Marine and Fisheries Research Institute (Kisumu Centre) as head of research on Fish quality management and Value addition. He completed his PhD studies (Food science) in 2015 at the University of Iceland, through the UNU-FTP scholarship programme.
Increasing the value of small fish species for human consumption through improving drying and packaging
Drying is an affordable fish preservation method that is commonly used in most developing countries where poorly developed logistics limit marketing of fresh fish. In Eastern Africa dried Silver cyprinid (locally known as Dagaa) is an important source of low cost stable dietary protein. Dagaa catch from Lake Victoria has exceeded half a million tons in recent years constituting about 60% of the total catch. Despite being the main fishery of Lake Victoria, it’s considered third in terms of value. This is because dried dagaa is often of low quality, restricting the sales to low income groups shopping in open-air markets. The fishery is also characterized by high postharvest losses against a background of food insecurity. Lately, there is an increasing demand among middle class consumers for dried small fish of high quality sold in supermarkets. Increased demand for dried small fish could be met by improved processing methods or imports. The aim of this study was to improve the quality and safety of dried small fish, and study acceptability of new products such as dried capelin in markets accustomed to dried small fish. The effects of blanching and drying methods on fish quality were evaluated. The influence of lipid content and packaging methods on lipid degradation, sensory properties and microbial quality during storage of dried fish was assessed, as well as the marketing potential of sardine dried under more hygienic conditions and imported dried capelin.
Blanching prior to drying of fish resulted in low quality and sensory properties, and protein denaturation. Fat content of capelin depends on the time of year and when capelin of 9-10% lipid content rather than 7-7.5% was used, drying rate was reduced and moisture content in the end product increased, while the fat protected proteins during blanching and drying. Drying under controlled conditions improved quality demonstrating the need for developing a commercial drier for processing of small fish. Industrially dried capelin and sardine were found to be rich in essential polyunsaturated fatty acids, with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) constituting approximately 13% and 20% of the total fatty acids of these fish respectively. Lipid content influenced hydrolysis and oxidation as well as sensory properties during storage of dried capelin. When atmospheric oxygen was removed by vacuum packaging, dried fatty capelin became more stable during storage with less lipid degradation, less rancid odour and lower counts of microbes. Vacuum packaging had no influence on lipid hydrolysis. Improved dried sardine and capelin received high acceptability ratings, indicating consumers of traditional dried small fish might accept new dried fish products. The results from this study show that well processed and packaged dried small fish can be highly nutritious and could contribute to the reduction of malnutrition prevailing in East African countries.